1. Contact: Jaehwan Kim, ETRI, Korea
Nov. 2008
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: In-body Channel modeling for WBAN with various frequency bands
Date Submitted: [7 Nov., 2008]
Source: Jaehwan Kim[ETRI], HyungSoo Lee[ETRI], Jae-Young Kim[ETRI], Jeong Ki Pack[CNU], and Tae Hong Kim[CNU]
Contact: Jaehwan Kim, ETRI, Korea
Voice: ,
Re: [n/a]
Abstract: Provide channel modeling for in-body communication communication system
Purpose: To provide basic channel characteristics for the manufacture of in-body communication system
Notice: This document has been prepared to assist the IEEE P It is offered as a basis for discussion and is not binding on the contributing individual's or organization's. The material in this document is subject to change in form and content after further study. The contributor's reserves the right to add, amend or withdraw material contained herein.
Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and maybe made publicly available by P

2. Contents Channel models for BAN Simulation Scenario
Nov. 2008
Contents
Channel models for BAN
Simulation Scenario
Channel modeling for MICS
Channel modeling for ISM band
Conclusion

3. Channel models for WBAN
Nov. 2008
Channel models for WBAN
Scenario
Description
Frequency Band
Channel Model S1
Implant to Implant
MHz
CM1 S2
Implant to Body Surface
CM2 S3
Implant to External S4
Body Surface to Body Surface (LOS)
TBD (f1,… fn)
CM3 S5
Body Surface to Body Surface (NLOS) S6
Body Surface to External (LOS)
CM4 S7
Body Surface to External (NLOS) .

4. Simulation scenario Transmitter location : 17 positions
Nov. 2008
Simulation scenario
Transmitter location : 17 positions
Near surface implants : 9
Deep tissue implants : 8 16 15 1 2
Location
Device
Deep tissue
Capsule endoscope, Capsule for drug delivery(1-4, 6-9)
Near surface
Glucose-Insulin(10-11), Insulin pump(12-13)
Pacemaker(14)
Deep brain stimulator, Parkinson’s disease, Cortical stimulator, Visual neuro-stimulator, Audio-neuro stimulator(15-16)
Central-nerve stimulator(11)
Healthcare shoes (17) 14 3 11 4 12 7 13 6 5 8 10 9
Receiver location : 286 points
Implants(in-body) : 148
Body surface : 138 17

5. Channel modeling Path loss model
Nov. 2008
Channel modeling
Path loss model
- Path loss model used in IEEE P
- PL(d)=PL(d0)+10nlog10(d/d0)+S [dB]
d0 : reference distance, 50 mm
n : path loss exponent
S : random scatter around the regression line, N(0, σs)

6. Path Loss vs. Distance Scatter Plot(CM1) <MICS>
Nov. 2008
Path Loss vs. Distance Scatter Plot(CM1)
<MICS>
Deep tissue implant to another
implant
Near surface implant to another
implant
( n=5.39, PL(d0)=39.30, σs=7.11 )
(n=4.00, PL(d0)=44.87, σs=9.01)

7. Path Loss vs. Distance Scatter Plot(CM2) <MICS>
Nov. 2008
Path Loss vs. Distance Scatter Plot(CM2)
<MICS>
Deep tissue implant to body surface
Near surface implant to body
surface
(n=4.58, PL(d0)=43.6, σs=6.18)
(n=3.58, PL(d0)=46.5, σs=8.85)

8. Implant to body surface
Nov. 2008
<Implant to Implant CM1 (Scenario S1)>
<Implant to Body surface CM2 (Scenario S2)>
Implant to Implant
PL(d0) n σs
Deep tissue
39.30
5.39
7.11
Near surface
44.87
4.00
9.01
Implant to body surface
PL(d0) n σs
Deep tissue
43.60
4.58
6.18
Near surface
46.50
3.58
8.85

9. Path Loss vs. Distance Scatter Plot(CM1) <ISM (900 MHz)>
Nov. 2008
Path Loss vs. Distance Scatter Plot(CM1)
<ISM (900 MHz)>
Deep tissue implant to another
implant
Near surface implant to another
implant
( n=6.34, PL(d0)=38.22, σs=10.52 )
(n=4.39, PL(d0)=42.59, σs=12.59)

10. Path Loss vs. Distance Scatter Plot(CM2) <ISM (900 MHz)>
Nov. 2008
Path Loss vs. Distance Scatter Plot(CM2)
<ISM (900 MHz)>
Deep tissue implant to body surface
Near surface implant to body
surface
(n=5.12, PL(d0)=45.24, σs=8.38)
(n=3.91, PL(d0)=43.58, σs=11.97)

11. Implant to body surface
Nov. 2008
<Implant to Implant CM1 (Scenario S1)>
<Implant to Body surface CM2 (Scenario S2)>
Implant to Implant
PL(d0) n σs
Deep tissue
38.22
6.34
10.52
Near surface
42.59
4.39
12.59
Implant to body surface
PL(d0) n σs
Deep tissue
45.24
5.12
8.38
Near surface
43.58
3.91
11.97

12. Path Loss vs. Distance Scatter Plot(CM1) <ISM(2.4 GHz)>
Nov. 2008
Path Loss vs. Distance Scatter Plot(CM1)
<ISM(2.4 GHz)>
Deep tissue implant to another
implant
Near surface implant to another
implant
( n=9.28, PL(d0)=50, σs=20.02 )
(n=2.57, PL(d0)=83.81, σs=19.69)

13. Path Loss vs. Distance Scatter Plot(CM2) <ISM(2.4 GHz)>
Nov. 2008
Path Loss vs. Distance Scatter Plot(CM2)
<ISM(2.4 GHz)>
Deep tissue implant to body surface
Near surface implant to body
surface
(n=4.62, PL(d0)=83.94, σs=12.75)
(n=2.74, PL(d0)=71.59, σs=17.04)

14. Implant to body surface
Nov. 2008
<Implant to Implant CM1 (Scenario S1)>
<Implant to Body surface CM2 (Scenario S2)>
Implant to Implant
PL(d0) n σs
Deep tissue
50.00
9.28
20.02
Near surface
83.81
2.57
19.69
Implant to body surface
PL(d0) n σs
Deep tissue
83.94
4.62
12.75
Near surface
71.59
2.74
17.04

15. Modified Channel Model
Nov. 2008
Modified Channel Model
Path loss model
- PL(d)=PL(d0)+10nlog10(d/d0)+ a*d +S [dB]
d0 : reference distance, 50 mm
a : coefficient for absorption loss
n : path loss exponent, N(0, σs)
S : random scatter around the regression line
- The absorption loss of biological tissues is very large. Because the absorption loss is a linear term in a log scale, we tried a modified path loss model by adding the first order term to WBAN channel more accurately.

16. Path loss vs. Distance Scatter Plot(CM1) <403.5 MHz>
Nov. 2008
Path loss vs. Distance Scatter Plot(CM1)
<403.5 MHz>
Deep tissue implant to another
implant
Near surface implant to another
implant
(n=6.75, PL(d0)=33.04,
a=-25.31, σs=8.30)
(n=8.49, PL(d0)=29.06,
a=-36.81, σs=5.96)

17. Path loss vs. Distance Scatter Plot(CM2) <403.5 MHz>
Nov. 2008
Path loss vs. Distance Scatter Plot(CM2)
<403.5 MHz>
Deep tissue implant to body surface
Near surface implant to body surface
(n=5.83, pl=36.45,
a=-19.81, σs=8.33)
(n=7.99, PL(d0)=28.99,
a=-32.97, σs=5.19)

18. Implant to body surface
Nov. 2008
The modified pass loss model seems to be better, in terms of the modeling accuracy (i. e. standard deviation σs).
<Implant to Implant CM1 (Scenario S1)>
<Implant to Body surface CM2 (Scenario S2)>
Implant to Implant
PL(d0) n a σs
Deep tissue
29.06
8.49
-36.81
5.96
Near surface
33.04
6.75
-25.31
8.30
Implant to body surface
PL(d0) n a σs
Deep tissue
28.99
7.99
-32.97
5.19
Near surface
36.45
5.83
-19.81
8.33

19. Path loss vs. Distance Scatter Plot(CM1) <900 MHz>
Nov. 2008
Path loss vs. Distance Scatter Plot(CM1)
<900 MHz>
Deep tissue implant to another
implant
Near surface implant to another
implant
(n=7.75, PL(d0)=28.13,
a=-30.95, σs=11.8)
(n=10, PL(d0)=26.53,
a=-44.49, σs=9.12)

20. Path loss vs. Distance Scatter Plot(CM2) <900 MHz>
Nov. 2008
Path loss vs. Distance Scatter Plot(CM2)
<900 MHz>
Deep tissue implant to body surface
Near surface implant to body surface
(n=6.45, pl=32.21,
a=-22.4, σs=11.49)
(n=9.64, PL(d0)=25.9,
a=-43.64, σs=7.11)

21. Implant to body surface
Nov. 2008
<Implant to Implant CM1 (Scenario S1)>
<Implant to Body surface CM2 (Scenario S2)>
Implant to Implant
PL(d0) n a σs
Deep tissue
26.53
10.00
-44.49
9.12
Near surface
28.13
7.75
-30.95
11.80
Implant to body surface
PL(d0) n a σs
Deep tissue
25.90
9.64
-43.64
7.11
Near surface
32.21
6.45
-22.40
11.49

22. Path loss vs. Distance Scatter Plot(CM1) <2.4 GHz>
Nov. 2008
Path loss vs. Distance Scatter Plot(CM1)
<2.4 GHz>
Deep tissue implant to another
implant
Near surface implant to another
implant
(n=7.53, PL(d0)=62.50,
a=-45.58, σs=18.59)
(n=10, PL(d0)=66.31,
a=-46.79, σs=16.32)

23. Path loss vs. Distance Scatter Plot(CM2) <2.4 GHz>
Nov. 2008
Path loss vs. Distance Scatter Plot(CM2)
<2.4 GHz>
Deep tissue implant to body surface
Near surface implant to body surface
(n=6.17, pl=56.27,
a=-30.17, σs=16.43)
(n=9.98, PL(d0)=61.01,
a=-51.74, σs=11.62)

24. Implant to body surface
Nov. 2008
<Implant to Implant CM1 (Scenario S1)>
<Implant to Body surface CM2 (Scenario S2)>
Implant to Implant
PL(d0) n a σs
Deep tissue
66.31
10.00
-46.79
16.32
Near surface
62.50
7.53
-45.58
18.59
Implant to body surface
PL(d0) n a σs
Deep tissue
61.01
9.98
-51.74
11.62
Near surface
56.27
6.17
-30.17
16.43

25. Comparison of Path Loss (30 cm distance)
Nov. 2008
Comparison of Path Loss (30 cm distance)
MICS
900 MHz
2.4 GHz
Path loss
Std.
CM1
Deep tissue
88.35
7.11
98.07
10.52
142.23
20.02
Near surface
76.01
9.01
89.34
12.59
123.50
19.69
CM2
85.42
6.18
83.46
8.38
132.64
12.75
83.21
8.85
85.97
11.97
109.95
17.04
<Modified model>
MICS
900 MHz
2.4 GHz
Path loss
Std.
CM1
Deep tissue
90.04
5.96
100.12
9.12
118.78
16.32
Near surface
86.27
8.30
90.95
11.8
125.73
18.59
CM2
86.46
5.19
94.93
7.11
134.77
11.62
84.20
8.33
87.17
11.49
111.66
16.43

26. Conclusion The attenuation loss is increased since not only
Nov. 2008
Conclusion
When radio frequency increases
The attenuation loss is increased since not only
radiation loss but also conductivity rise.
Finally, the path loss will be increased, too.
The channel model in 2.4GHz is worse than in 400MHz
or 900MHz in Accuracy. (larger σs)

27. Thank you for your attention!
Nov. 2008
Thank you for your attention!
Q & A.